Natarajan's letter to Sonia Gandhi "conclusively establishes" that it was not the statutory or mandatory considerations which weighed with the Congress but only "whims" of the leaders, the Finance Minister charged.

"I hope the Environmental ministry now will go into each of these permissions which were granted and not granted and make sure that these are expeditiously dealt with only as per law and no other consideration," Jaitley said.

The Finance Minister was reacting to Natarajan's letter to the Congress President alleging that she had received specific requests from Rahul Gandhi on environmental clearances and consequently had rejected big ticket projects.

Speaking to reporters here, Jaitley said during UPA's regime, the growth rate was radically going down and one of the prime reasons for that was delay in approvals being granted to projects. He said Natarajan's letter "conclusively establishes" that it was not the statutory or mandatory considerations which weighed with the ruling party.

"But what weighed with them was the whims of political leaders of the party as to who is to be granted environmental permission and who is not to be granted an environmental permission," the Finance Minister said.

In a scenario where whims overtake legal requirements, it becomes a textbook case of "crony capitalism, which the UPA was practising," he said.

Attacking the UPA regime further, Jaitley said that it was a practitioner of a "sadistic" economy which was vindictive in nature, wanting to teach some people a lesson while wanting to favour some others. "This obviously had to be for corrupt and collateral reasons," he charged.